Are hepatic portal venous system components distributed equally in the liver? A multidetector computerized tomography study.

OBJECTIVE We aimed to evaluate the relationships between the splenic index, right and left hepatic lobe volumes, diameters of splenic vein (SV), superior mesenteric vein (SMV) and the portal vein (PV) by Multidetector Computerized Tomography (MDCT). We also investigated indirect signs of portal venous flow pattern using these parameters. MATERIAL AND METHODS Following their contrast thoracoabdominal and abdominal 64-MDCT examinations, the images of 100 cases (61 males and 39 females) were evaluated retrospectively. For each case, the splenic index, total hepatic volume, left and right hepatic volumes were calculated on the post-contrast portal venous phase (50(th) sec) images. Spearman correlation tests were carried out with the purpose of determining the relationships between the variables. Statistical significance level was set at p<0.005. RESULTS A statistically significant relation was demonstrated between the diameter of the SMV and right hepatic lobe volume (p<0.0001), and according to Pearson's correlation analysis, a positive correlation of medium strength (r=0.36) was observed. A positive correlation was demonstrated between the diameter of the splenic vein and left hepatic lobe volume (r=0.36). Statistically significant relation between the diameters of the splenic vein and right hepatic lobe was not observed (p=0.62). A strong correlation between the left hepatic lobe volume and the splenic index (r=0.556) was observed. CONCLUSION We observed a positive correlation and a significant relation between the diameter of the SMV and the right hepatic lobe, and a relation between the splenic vein and splenic index and both hepatic lobes. We believe that this situation is related to the streamline flow in the portal vein, and as demonstrated in the literature, the flow in the SMV is directed at the right lobe, whereas the splenic vein empties into the liver homogenously. Our study is the first study in the literature performed by multidetector CT, which is a technique that reveals the relations between the streamline flow in the portal vein, the splenic index and the hepatic lobe volumes.